Hello, I am trying to get an estimate of electron transfer rate between ions and it seems like Marcus theory is recommended by a lot of people. For the lambda term or reorganization energy part of that theory, I have followed the 4-points calculation but however it seems will fail for monoatomic entities, in those cases i am not sure if it is because monoatomic ions do not have a "structure", but the gaussian does give me exactly SCF for the ion that calculated using neutral check file and the ion that is directly optimized. Has anybody facing this problem before? I wonder if there is any solutions or alternatives. Thank you! (My interest is in gas phase so no solvent is specified).